I've have seen many PANSS and MADRS graphs showing the magnitude of the placebo effect in psychiatric disorders, which is astonishing in isolation. However, many studies quit the placebo after 4-6 weeks, despite the placebo effect being in full force and not remitting for the duration of administration. Thus, does the placebo effect taper off or decline with time in other studies that administer it beyond the 4-6 week duration?